The Chromatographic Estimation of Lysine and Some Applications of the Method

Abstract

Small volumes (0.02 ml.) of Cu salts of amino acids are partitioned on paper strips in an aqueous phenol atmosphere for 6 hrs., the strips are then air-dried and developed by painting with fresh 10% aqueous Fe ferrocyanide. The position and spread of the resulting bands of pink Cu ferrocyanide indicate the nature and quantity of amino acids present. Tests using 60 [mu]g. of various amino acids show the lysine band to be particularly con- sistent occurring in the 0.42-0.50 Rf zone; glutamic and aspartic acids overlap in the 0.08-0.10 zone, arginine and histidine overlap in 0.55-0.62 zone, glycine, serine, threonine, valine, leucine, iso-leucine, tyrosine, proline, and hydroxyproline are in the zone 0.7-1.0. Tryptophan, methionine, cystine and phenylalanine are oxidized in the process, and cannot be identified by this process. The band spread of the Cu lysine salt is proportional to the concn. in the range 30-60 [mu]g. Results of the detn. of lysine concn. in urine of adults and infants on various diets are reported. Infants on wheat gluten diet supplemented with 6% D-lysine showed great increase in urinary lysine, while supplementing with 6% L-lysine returned values to normal, thus indicating that D-lysine is not utilized for growth by infants.